Note 4 - Loans and Allowance for Credit Losses (Detail) - Aging Analysis And The Recorded Investments In Loans (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Loans 30-59 Days Past Due	$ 23,742
Loans 60-89 Days Past Due	18,065
Loans 90 Day sor More Past Due	32,423
Total Past Due Loans	74,230
Current Loans	2,323,439
Total Invetsment in Loans	2,397,669	2,056,256	2,029,645
Consumer Loan [Member]
Loans 30-59 Days Past Due	9,031
Loans 60-89 Days Past Due	5,201
Loans 90 Day sor More Past Due	5,282
Total Past Due Loans	19,514
Current Loans	514,619
Total Invetsment in Loans	534,133
Commercial Real Estate Investment [Member]
Loans 30-59 Days Past Due	1,082
Loans 60-89 Days Past Due	2,626
Loans 90 Day sor More Past Due	3,647
Total Past Due Loans	7,355
Current Loans	935,415
Total Invetsment in Loans	942,770	756,645	772,728
Commercial Real Estate Owner Occupied [Member]
Loans 30-59 Days Past Due	2,593
Loans 60-89 Days Past Due	4,081
Loans 90 Day sor More Past Due	2,374
Total Past Due Loans	9,048
Current Loans	297,100
Total Invetsment in Loans	306,148	250,174	245,497
Residential Mortgage [Member]
Loans 30-59 Days Past Due	743
Loans 60-89 Days Past Due	107
Loans 90 Day sor More Past Due	713
Total Past Due Loans	1,563
Current Loans	56,389
Total Invetsment in Loans	57,952	39,552	37,662
Home Equity Line of Credit [Member]
Loans 30-59 Days Past Due	148
Loans 60-89 Days Past Due	726
Loans 90 Day sor More Past Due	670
Total Past Due Loans	1,544
Current Loans	97,386
Total Invetsment in Loans	98,930	97,103	94,008
Consumer, Other [Member]
Loans 30-59 Days Past Due	7
Loans 60-89 Days Past Due	15
Loans 90 Day sor More Past Due	7
Total Past Due Loans	29
Current Loans	5,014
Total Invetsment in Loans	5,043	4,227	4,218
Construction Loans [Member]
Loans 30-59 Days Past Due	10,138
Loans 60-89 Days Past Due	5,309
Loans 90 Day sor More Past Due	19,730
Total Past Due Loans	35,177
Current Loans	417,516
Total Invetsment in Loans	$ 452,693	$ 429,669	$ 405,429